1. Field of the Invention
The present invention relates to a laser induced thermal imaging apparatus and a fabricating method of an organic light emitting diode using the same, and more particularly to a laser induced thermal imaging apparatus and a fabricating method of an organic light emitting diode using the same, which laminate a donor film and an acceptor substrate using magnetic force.
2. Discussion of Related Art
An organic light emitting device includes a light emitting layer formed between the first and second electrodes, and emits light when a voltage is applied between the electrodes. A laser induced thermal imaging (LITI) process may be used to fabricated the organic light emitting device.
In general, at least a laser, an acceptor substrate and a donor substrate (or donor film) are needed for the laser induced thermal imaging. In a laser induced thermal imaging method, the laser is radiated to a donor substrate including a base substrate, a light-to-heat conversion layer (LTHC) and a transfer layer (or imaging layer) to convert the laser that passes through the base substrate into heat at the light-to-heat conversion layer, such that the light-to-heat conversion layer is deformed and expanded. This way, the transfer layer adjacent to the light-to-heat conversion layer is also deformed and expanded, and transferred to (or imaged on) the acceptor substrate.
When performing the laser induced thermal imaging method, a chamber in which the transfer is performed typically becomes a vacuum state. However, in the prior art, there has been a problem in that the transfer layer is not transferred well because space (or a gap) or impurities are created between the donor substrate and the accepter substrate when a laser-to-heat conversion is performed in the vacuum state. Therefore, in the laser induced thermal imaging method, a method of laminating the donor and accepter substrates is important, and to resolve the problems with the space or the impurities, various methods have been investigated.
FIG. 1 is a cross-sectional view that shows a prior art laser induced thermal imaging apparatus 10 for resolving the above-mentioned problem. According to FIG. 1, the laser induced thermal imaging apparatus 10 includes a substrate stage 12 placed in a chamber 11 and a laser radiating apparatus 13 placed at an upper portion of the chamber 11. The substrate stage 12 is a stage for placing an accepter substrate 14 and a donor film 15 introduced in the chamber 11 in turn.
The acceptor substrate 14 and the donor film 15 are laminated to each other prior to transferring the transfer layer of the donor film 15 to the acceptor substrate 14. During lamination, the chamber 11 is typically not maintained in the vacuum state, but a vacuum pump P is used to absorb impurities. Since the chamber is not in a vacuum state during lamination, the reliability or the lifetime of the resulting organic light emitting device can be reduced because of oxygen, moisture, or the like in the chamber 11.
On the other hand, when the chamber 11 is maintained in the vacuum state during lamination, it is difficult to absolutely prevent creation of impurities 1 and space between the accepter substrate 14 and the donor film 15.